The present patent application relates to surface cleaning systems, and, more particularly, to a surface cleaning system that utilizes a regenerative blower as a vacuum source.
Cleaning carpet, upholstery, tile floors, and other surfaces enhances the appearance and extends the life of such surfaces by removing the soil embedded in the surface. Moreover, carpet cleaning removes allergens, such as mold, mildew, pollen, pet dander, dust mites, and bacteria. Indeed, regular cleaning keeps allergen levels low and thus contributes to an effective allergy avoidance program.
Vacuum extractors for cleaning surfaces, such as carpet, typically deposit a cleaning fluid upon the carpet or other surface to be cleaned. The deposited fluid, along with soil entrained in the fluid, is subsequently removed by high vacuum suction. This enables the carpet to be completely dry before mold has time to grow. The soiled fluid, i.e., waste fluid, is then separated from the working air and is collected in a recovery tank.
Due to the prevalence of carpeted surfaces in commercial establishments, institutions, and residences, there exists a thriving commercial carpet cleaning industry. In order to maximize the efficacy of the cleaning process, industrial floor cleaning systems should be powerful to minimize the time in which the soil entrained cleaning fluid is present in the carpet. Industrial floor cleaning systems should also be durable. That is, such a cleaning system should be manufactured from durable working parts so that the system has a long working life and requires little maintenance.
Industrial floor cleaning systems generally provide for the management of heat, vacuum, pressure, fresh and gray water, chemicals, and power to achieve the goal of efficient, thorough cleaning of different surfaces, usually carpets but also hard flooring, linoleum and other surfaces, in both residential and commercial establishments. Professional surface cleaning systems are also utilized in the restoration industry for water extraction.
Of the many industrial surface cleaning systems available, a major segment are self-contained having an own power plant, heat source, vacuum source, chemical delivery system, and water dispersion and extraction capabilities. These are commonly referred to as “slide-in” systems and install permanently in cargo vans, trailers, and other commercial vehicles, but can also be mounted on portable, wheeled carts. Slide-in systems comprise a series of components designed and integrated into a package with an overall goal of performance, economy, reliability, safety, useful life, serviceability, and sized to fit in various commercial vehicles.
Currently, the vacuum source found in the industrial surface cleaning systems comprises a positive displacement blower. One common type of positive displacement blower is a rotary blower. Rotary blowers typically include two or more meshing lobes that rotate within a blower chamber. In operation, as the lobes rotate, air is trapped in pockets surrounding the lobes and is carried from an intake side of the blower to an exhaust side of the blower. Positive displacement blowers are designed such that there is no contact between the lobes and the walls of the blower chamber, and the air is trapped due to the substantially low clearance between the components. However, because of the clearance that must be maintained between the lobes and the chamber walls, single-stage blowers can pump air across only a limited pressure differential. Furthermore, if the blower is used outside of its specified operating conditions, the compression of the air can generate such a large amount of heat that the lobes may expand to the point that they become jammed within the blower chamber, thereby damaging the pump. Because of the limited pressure differential that can be generated by a single-stage blower and the potential for damaging the blower if blower is run too hot, some industrial surface cleaning systems use blowers having multiple stages, which adds to the cost of the blower.
Positive displacement pumps, while popular, have several downfalls associated with their use. As discussed above, because rotary blowers are sensitive to heat, there is a risk of damaging the blower if the operation of the blower is not carefully monitored. Damage to the blower can include, for example, timing issues, clashing of the lobes, and total blower failure due to jamming of the components within the blower housing. Over time, reliability can also be an issue if proper maintenance is not performed. Rotary blowers also produce a significant amount of vibration during operation, which can lead to increased wear and tear on the blower and adjacent components of the cleaning system. Furthermore, rotary blowers can be very noisy. The noise produced by rotary blowers is not only a nuisance to those in the vicinity of the cleaning system, but it can also contribute to hearing loss if proper ear protection is not worn.